The U.S. House of Representatives has voted to undo three federal waivers that let California set strict vehicle pollution standards. On Wednesday, the House voted against two waivers involving heavy trucking, and on Thursday, it voted to reverse a state rule that would require all new vehicles in the state to be zero-emission by 2035.

Two nonpartisan government entities have advised Congress that it can’t actually reverse those waivers through the mechanism it’s using. The senate now needs to decide whether to follow that guidance — or follow the House.

California’s standards have been described by supporters as ambitious, and by critics as unrealistic. Beginning with model year 2026, the state requires 35% of new cars sold by any given automaker to be zero-emission. Currently, about 25% of new cars sold in California are electric; the national average is closer to 10%.

These rules are not something automakers can brush off or overlook. California is a huge state and a major auto market. Other states can’t set their own standards, but they can opt to follow California’s, and about a dozen have adopted its zero-emission rule. The result is that more than 30% of the U.S. auto market is governed by California’s policies.

California’s waiver has a massive impact, Stephanie Brinley, the associate director of AutoIntelligence at S&P Global Mobility, wrote in a report in January 2025.

Stephanie brinley, S&P Global Mobility

The Alliance for Automotive Innovation, a trade group representing automakers, had pushed hard for Congress to step in and overrule California because they argue that consumer demand for EVs is not strong enough to support California’s targets. John Bozzella, the trade group’s president, has warned that meeting the requirements would “take a miracle” and said in a statement Wednesday that thousands of American auto jobs and millions of units of U.S.auto production are at stake.

environmental groups such as the Union of concerned Scientists argue that flexibilities built into the rules make them more achievable than they seem. and they say stricter regulations are notable for protecting public health and the climate.

This vote is an unprecedented and reckless attack on states’ legal authority to address the vehicle pollution causing asthma, lung disease and heart conditions, Kathy Harris, Director of Clean Vehicles at the Natural Resources Defense Council, wrote in a statement.

Kathy Harris, Natural Resources Defense Council

Here’s how we got here, and what’s next.

What is a “California waiver”?

Picture Los Angeles in the 1940s and ’50s. Lovely beaches, palm trees and picturesque homes — that were unfeasible to see behind a thick haze. That choking smog was fueled by air pollution from cars and industry, which became trapped mid-air by mountains and wind patterns.

Facing this unusually severe problem, the state began regulating air pollution well before the federal government did. As an inevitable result, California has a unique privilege: It, alone among U.S. states, can impose its own emissions standards that are stricter than the nation’s.

Each time California wants to add a new, stricter rule, it has to obtain a waiver from the EPA. It’s done that more than 75 times.

Today, the House voted to rescind the waiver that let California issue its zero-emission rule for passenger cars, along with two more that allow california to set rules for heavy trucks. One rule would require more heavy trucks to be electric, while the other would require new diesel vehicles to become cleaner.

Those three California rules aren’t just about reducing smog. Cars and trucks are a major source of the carbon dioxide emissions that are warming the planet. Increasingly, California has become a global leader in reducing the carbon emissions that fuel climate change,and zero-emission vehicles are a key part of those climate policies.